Changes Of Topological Properties In Resting State Brain Network In Obsessive-compulsive Disorder

BackgroundObsessive-compulsive disorder（OCD）is a chronic and disabling disorder characterized by recurring,intrusive thoughts in the brain that cause distress and interfere with normal functioning,often accompanied by anxiety or depression in severe cases symptom.A survey shows that from 2000 to 2015,the current prevalence of OCD in mainland China 0.90%,and the lifetime prevalence is 3.17%.In the United States,the incidence of obsessive-compulsive disorder is 2%.OCD usually has an early onset and affects the patient’s life,resulting in a decline in the quality of life and productivity of the patient and their family members,as well as higher medical expenses for the patient’s family,and a greater socioeconomic burden.Also,patients with OCD have a decline in higher cognitive functions such as attention,memory,decision-making ability,and inhibitory function,but the underlying neuroimaging mechanism is still unclear.Previous functional magnetic resonance imaging（f MRI）techniques on OCD have typically used a seed,a preselected brain region from which functional connectivity to all other brain regions has been calculated.From pulse-topulse of the f MRI scan,the correlation coefficients between the blood oxygen level dependent（BOLD）signals in the seeds and the BOLD signals in each other’s regions are calculated.In spite of simple,sensitive,and easy to be interpreted,the seed-based f MRI has some disadvantage including—that the results are seed-dependent.Graph theory analysis is currently used as an alternative method for OCD patients because it allows to quantify the topology of the intrinsically connected networks.Calculated various graph-theoretic metrics that characterize the interconnectedness of entire networks and how individual nodes interact with the rest of the brain.Because these higher-level metrics are sensitive to effects that are undetectable by using seed-based f MRI,the brain networks have an advantage in the study of psychiatric disorders.However,the research on changes in the topological properties of brain functional networks in OCD,as well as the legal person correlation between changes in brain function and clinical symptoms.Therefore,the present study aimed at using graph theory to analyze the changes of the topological properties of the brain functional network in patients with OCD,in order to improve further understand of the central nervous regulation mechanism in OCD,and to provide scientific evidence for the diagnosis and efficacy evaluation of OCD..ObjectivesTo explore the research on the changes of the resting-state brain function network topology in patients with obsessive-compulsive disorder and its relationship with the disease course and clinical symptoms.MethodsA total of 34 patients with Obsessive-compulsive disorder（OCD group）and 35 healthy controls（HC group）matched for age,sex,and education level were included.Resting functional magnetic resonance imaging data were collected for all subjects,and the Yale-Brown Obsessive Compulsive Scale（Y-BOCS）was used to assess the severity of symptoms.Based on graph theory,the topological properties（global efficiency,small worldness property,nodal efficiency,nodal local efficiency,nodal clustering coefficient,nodal shortest path length,nodal degree centrality,nodal betweenness centrality）differences,extracting the topological attribute values of different brain regions in patients with obsessive-compulsive disorder and the Y-BOCS score for correlation analysis.Results1.Compared with the control group,the left temporal pole: the degree centrality of the superior temporal gyrus decreased in the obsessive-compulsive disorder group（P < 0.05）.2.Compared with the control group,the global efficiency,small-world metric,node clustering coefficient,node shortest path length,node global efficiency,node local efficiency and node betweenness centrality in the obsessive-compulsive disorder patient group The difference was not statistically significant,P > 0.05.3.In the left temporal pole of the patient group,the correlation between the degree centrality of the superior temporal gyrus and the course of the disease and the Y-BOCS score was not statistically significant,P > 0.05.Conclusions1.This study suggests that the topological attribute value of the temporal lobe,that is,degree centrality,has changed in patients with OCD,and suggests that the temporal lobe may play a certain role in the pathogenesis of OCD from the perspective of brain network.2.Changes in the topological properties of the left temporal epicosacrystal epicosa are not significantly associated with the course of obsessive-compulsive disorder and the severity of clinical symptoms.